Needle shutoff nozzles are used in injection molds to feed a flowable material at a predetermined temperature and high pressure to a separable mold insert. Most commonly they are fitted with pneumatically or hydraulically driven shutoff needles which periodically open and close gates in the mold insert. For that purpose each shutoff needle is supported in axially displaceable manner in the mold-side region of the injection mold and, in the nozzle-side region, passes preferably centrally through a flow duct for the material to be processed. The flow duct terminates in a nozzle element subtending a nozzle discharge aperture. In the closed position, the lower end of the shutoff needle engages a sealing seat constituted in the nozzle end or in the mold insert.